Bulb socket

Abstract: A bulb socket for receiving a bulb which has a plus electrode and a minus electrode comprises a socket housing, a plus terminal and a minus terminal. The plus terminal is mounted in the socket housing, and includes a bulb-side plus terminal portion for electrically connecting with the plus electrode of the bulb and a feeder-side plus terminal portion for electrically connecting with an external plus terminal. The bulb-side plus terminal portion and the feeder-side plus terminal portion are disposed in a juxtaposed condition within the socket hosing. The minus terminal is mounted in the socket housing, and includes a bulb-side minus terminal portion for electrically connecting with the minus electrode of the bulb and a feeder-side minus terminal portion for electrically connecting with an external minus terminal. The bulb-side minus terminal portion and the feeder-side minus terminal portion are disposed in a juxtaposed condition within the socket hosing.

Description: This invention relates to a bulb socket suited for use, for example, in a combination lamp of a vehicle. For example, in a rear combination lamp of a vehicle, a bulb is attached through a bulb socket to a back cover mounted between a trunk room and a rear portion of the vehicle. In such a bulb socket as shown in Fig. 4, a socket housing 2 of a substantially tubular shape is mountod through a gasket 1b in a mounting hole la in a back cover 1. Engagement pins 3b projecting from a peripheral surface of a base 3a of the bulb 3 are engaged respectively in J-shaped grooves 2a formed in an inner peripheral surface of the socket housing 2. The bulb 3 is fitted in the socket housing 2 to be fixed thereto. A plus metal terminal 4 and a minus metal terminal 5 are provided within the socket housing 2 in which the bulb 3 is to be fitted. A bulb-side plus terminal 4a, which is curved into a S-shape, and is adapted to contact a plus metal terminal 3c of the bulb 3, is formed at one end of the plus metal terminal 4, and a feeder-side male terminal 4b, constituting a feeder-side connection portion, is formed at the other end of this plus metal terminal. A bulb-side minus terminal 5a, adapted to abut against the base 3a of the bulb 3, is formed at one end of the minus metal terminal 5. A feeder-side male terminal (not shown), constituting a feeder-side connection portion, is formed at the other end of this minus metal terminal. The feeder-side male terminal 4b is disposed within a connector housing 6 which is projected downwardly beyond a bottom surface 2b of the socket housing 2. The feeder-side male terminal 4b is connected to a female terminal 8, which is insertod into the connector housing 6 through a rubber ring 7, to constitute the feeder-side connection portion. The feeder-side male terminal 4b is connected to an exterior feeder side. This feeder-side connection portion is projected from the bottom surface 2b of the socket housing 2 by a distance generally equal to the overall length of the female terminal 8. However, the above bulb socket has the feeder-side connection portion projected long from the bottom surface 2b of the socket housing 2, and therefore the dimension of the the bulb socket projecting from the back cover 1 toward the trunk room is long. As a result, when the bulb socket is mounted on the back cover mounted in a lamp-mounting space formed between the trunk room and the rear portion of the vehicle, the dimension of the bulb socket projecting from the back cover toward the trunk room is long, so that a sufficient operation space is not available, which results in the problem that the efficiency of the mounting operation is lowered. FR-A-2 240 544 shows a bulb socket the present invention has the most consistencies with. This known bulb socket uses a plus terminal, said plus terminal being bent so as to have a bulb-side portion being capable of elastically engaging the plus electrode of the bulb and a feeder-side terminal portion which extends to the outside of the socket body radially therefrom and parallel to the outer circumferencial wall of the socket body. The minus electrode is constituted by a ring having also a feeder-side terminal portion adjacent to the feeder-side plus terminal portion, said ring having two contact portions constituting the bulb-side minus terminal portions for receiving and holding the mounting pins of the bulb and for making electrical contact therewith. The present invention has been made in view of the above problems, and an object of the invention is to provide a bulb socket in which the dimension of projecting of a rear portion of a socket housing can be reduced. The present invention provides according to claim 1 thereof a bulb socket for receiving a bulb having a plus electrode and a minus electrode, said bulb socket comprising: a socket housing; a bulb hood inside said socket housing; a plus terminal mounted in said bulb hood, said plus terminal being bent so as to have a bulb-side plus terminal piece inside said bulb hood for electrically connecting with the plus electrode of said bulb and a feeder-side plus terminal piece extending out of said bulb hood for electrically connecting with an external plus terminal, said bulb-side plus terminal piece and said feeder-side plus terminal piece being disposed such that said feeder-side plus terminal piece does not extend beyond the plane of a bottom surface of said socket housing; and a minus terminal mounted in said bulb hood, said minus terminal being bent so as to have a bulb-side minus terminal piece inside said bulb hood for electrically connecting with the minus electrode of said bulb and a feeder-side minus terminal piece extending out of said bulb hood for electrically connecting with an external minus terminal, said bulb-side minus terminal piece and said feeder-side minus terminal piece being disposed such that said feeder-side minus terminal piece does not extend beyond the plane of said bottom surface of said socket housing, wherein said feeder-side plus terminal piece and said feeder-side minus terminal piece extend in respective connection holes defined between said socket housing and said bulb hood. In the bulb socket of the present invention, the bulb-side terminal portion and the feeder-side terminal portion are disposed in a juxtaposed condition within the socket housing, and therefore any portion projecting from the bottom surface of the socket housing can be eliminated. With this arrangement, the overall length of the socket housing can be reduced, and when this construction is actually mounted, the space occupied by the bottom side of the socket housing can be reduced. As described above, with the use of the bulb socket of the present invention, no portion projects from the bottom surface of the socket housing, and therefore there are achieved excellent advantages that the overall length of the socket housing can be reduced, and that even when this construction is to be mounted at a narrow place, the efficiency of the mounting operation is enhanced. The present invention can be more readily understood from the following detailed description, which is to be taken in conjunction with the accompanying drawings, in which: Fig. 1 is a vertical cross-sectional view of a bulb socket; Fig. 2 is a plan view of the bulb socket; Fig. 3 is a perspective view of a plus terminal; and Fig. 4 is a vertical cross-sectional view showing a conventional bulb socket. The embodiment to be described is directed to a bulb socket 20 to which a bulb B, used in a rear combination lamp of a vehicle, is attachable. As shown in Fig. 1, the bulb B comprises a bulb member a in which a filament is sealed, and a base b of electrically-conductive material mounted on a bottom portion of the bulb member a . A bulb electrode c connected to a plus side of the filament is mounted on the bottom of the base b through an insulation material, and a peripheral surface of the base b serves as a minus feeder electrode. A pair of mounting pins d (only one of which is shown) for attaching the bulb to a bulb socket 20 is formed on the peripheral surface of the base b . As shown in Fig. 1, the bulb socket 20 for receiving this bulb B comprises a socket housing 21 of a generally cylindrical shape, and a gasket g for mounting this socket housing 21 on a back cover E in an air-tight manner. A flange 22 is formed on the outer periphery of the socket housing 21, and is disposed adjacent to the bottom of this socket housing. The gasket g is held between the flange 22 and the back cover E, and in this condition the socket housing 21 is rotated, so that socket mounting projections 23 which are formed on right and left portions of the peripheral surface of the socket housing are engaged with a mounting hole formed in the back cover E, thereby mounting the socket housing in an air-tight manner (see Fig. 2). A bulb hood 24 of a cylindrical shape is provided within the socket housing 21. This bulb hood 24 is fitted on the base b of the bulb B. J-shaped grooves are formed in the inner peripheral surface of the bulb hood 24, and can receive the mounting pins d of the base b , respectively, so as to mount the bulb B. A minus terminal 31 for contact with the minus feeder electrode of the base b is mounted on the inner peripheral surface of the bulb hood 24. A plus terminal 32 for contact with the bulb electrode c is mounted on the bottom surface of the bulb hood 24. As shown in Fig. 3, the plus terminal 32 includes a bulb-side plus terminal piece 33 defined by a resilient contact portion of a generally S-shape, a feeder-side plus terminal piece 34 for connection to a feeder 40a for supplying power to the bulb B, and a connecting piece 35 holding the two terminal pieces in a juxtaposed condition. This plus terminal 32 is formed by bending a single electrically-conductive metal plate. As shown in Fig. 1, the plus terminal 32 is inserted into the bulb hood 24 in a direction of the length of this bulb hood, and a resilient withdrawal prevention piece 41a is engaged with a retaining portion 42a of the bulb hood 24, thereby securing this plus terminal to the bulb hood. The bulb-side plus terminal piece 33, forming the generally S-shaped, resilient contact portion, is disposed within the bulb hood 24 so as to abut against the bulb electrode c formed on the bottom surface of the bulb B. The feeder-side plus terminal piece 34 formed at the other end of the plus terminal is in the form of a tab defining a connection portion for connection to the feeder 40a for supplying power to the bulb B. This tab extends through a hole 43a into a connection hole 44a formed in a back surface of the socket housing 21. On the other hand, the minus terminal 31 includes a bulb-side minus terminal piece 36 serving as a resilient contact portion for contact with the minus feeder electrode of the base b of the bulb B, a feeder-side minus terminal piece 37 for connection to a feeder 40b, and a connecting piece 38 holding the two terminal pieces in a juxtaposed condition. This minus terminal is formed by bending a single electrically-conductive metal plate. The minus terminal 31 is inserted into the bulb hood 24 in the direction of the length of this bulb hood, and a resilient withdrawal prevention piece 41b is engaged with a retaining portion 42b of the bulb hood 24, thereby securing the minus terminal to the bulb hood. The bulb-side minus terminal piece 36, defining the tongue-like resilient contact portion, is adapted to abut against the base b of the bulb B received in the bulb hood 24. The feeder-side minus terminal piece 37, formed at the other end of the minus terminal, is in the form of a tab defining a connection portion for connecting the feeder 40b to the bulb B. This tab extends through a hole 43b into a connection hole 44b formed in the back surface of the socket housing 21. Receptacles 45a and 45b are attached respectively to the feeders 40a and 40b for supplying power to the bulb B, and can be fitted on and connected to the feeder-side plus terminal piece 34 and the feeder-side minus terminal piece 37, respectively. Waterproof rubber packings 46a and 46b are mounted respectively on proximal end portions of the receptacles 45a and 45b, and can be fitted in the connection holes 44a and 44b, respectively. Next, the operation of this embodiment will be described. When the bulb B is attached to the bulb hood 24 of the bulb socket 20, the bulb electrode c of the bulb B and the base b are resiliently contacted respectively with the plus terminal 32 and the minus terminal 31, thereby making electrical connection therebetween. At this time, the bulb-side plus terminal piece 33 and the feeder-side plus terminal piece 34 of the plus terminal 32 are disposed in a juxtaposed condition within the bulb socket 20. Also, the bulb-side minus terminal piece 36 and the feeder-side minus terminal piece 37 of the minus terminal 31 are disposed in a juxtaposed condition within the bulb socket 20. Therefore, with the use of the bulb socket 20 of this embodiment, no portion projects from a bottom surface 21a of the socket housing 21, and therefore the overall length of the socket housing 21 can be reduced, and even when a rear combination bulb of a vehicle or the like is to be mounted at a narrow place, the efficiency of the mounting operation is enhanced. Moreover, if there is obtained generally the same operation space as available with the conventional construction, the capacity of a trunk room can be increased by an amount corresponding to the amount of reduction of the overall length of the socket housing 21. The present invention is not limited to the above embodiment, and for example, instead of the bulb B, a wedge base bulb can be used. Although each of the plus terminal and the minus terminal 31 is formed by bending a single electrically-conductive metal plate, each terminal may be formed, for example, in such a manner that the two terminal pieces of each terminal are separate from each other, and are connected together in an electrically conductive manner. Although the bulb B has the single bulb electrode c, the invention can be applied to the type in which two bulb electrodes and one common electrode are provided.

Claims: A bulb socket for receiving a bulb (B) having a plus electrode and a minus electrode, said bulb socket (20) comprising: a socket housing (21); a bulb hood (24) inside said socket housing (21); a plus terminal (32) mounted in said bulb hood (24), said plus terminal (32) being bent so as to have a bulb-side plus terminal piece (33) inside said bulb hood (24) for electrically connecting with the plus electrode of said bulb (B) and a feeder-side plus terminal piece (34) extending out of said bulb hood (24)) for electrically connecting with an external plus terminal, said bulb-side plus terminal piece (33) and said feeder-side plus terminal piece (34) being disposed such that said feeder-side plus terminal piece (34) does not extend beyond the plane of a bottom surface (21a) of said socket housing (21); and a minus terminal (31) mounted in said bulb hood (24), said minus terminal (31) being bent so as to have a bulb-side minus terminal piece (36) inside said bulb hood (24) for electrically connecting with the minus electrode of said bulb (B) and a feeder-side minus terminal piece (37) extending out of said bulb hood (24) for electrically connecting with an external minus terminal, said bulb-side minus terminal piece (36) and said feeder-side minus terminal piece (37) being disposed such that said feeder-side minus terminal piece (37) does not extend beyond the plane of said bottom surface (21a) of said socket housing (21), wherein said feeder-side plus terminal piece (34) and said feeder-side minus terminal piece (37) extend in respective connection holes (44a, 44b) defined between said socket housing (21) and said bulb hood (24). The bulb socket according to claim 1, wherein said socket housing (21) has a cylindrical shape and said feeder-side plus terminal piece (34) and said feeder-side minus terminal piece (37) are disposed on the cylindrical wall of said socket housing (21). The bulb socket according to claim 1 or 2, wherein said feeder-side plus terminal piece (34) and said feeder-side minus terminal piece (37) are disposed in the same height from said bottom surface (21a) of said socket housing (21).

Inventors: UCHIYAMA TAKAHIRO, UCHIYAMA, TAKAHIRO, UCHIYAMA, TAKAHIRO, C/O SUMITOMO WIRING
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1994
Main classification: H01R33
IPC codes: H01R33, F21V19